Silicon-Directed Regio- and Enantioselective Synthesis of ?-Hydroxy-ketones Preliminary Communication
作者:Braj B. Lohray、Dieter Enders
DOI:10.1002/hlca.19890720514
日期:1989.8.9
rolidine (RAMP)-hydrazone method, are oxidized to give α-hydroxy-ketones (R)−5 of high enantiomeric purity (ee ≥ 98%) and in good overall yields (51-70%). The key step of the procedure is the silicon-directed diastereoselective oxidation of the corresponding silyl enol ethers of (S)−2, with m-chloroperbenzoic acid or 3-phenyl-2-(phenylsulfonyl)oxaziridine, followed by flash chromatography and desilylation
α-甲硅烷基酮(S)-2(ee≥98%),可通过(-)-(S)-1-氨基-2-(甲氧基甲基)吡咯烷酮(SAMP)从甲酮1进行甲硅烷基化或甲硅烷基化/烷基化将-/(+)-(R)-1-氨基-2-(甲氧基甲基)吡咯烷(RAMP)-method方法氧化,得到高对映体纯度(ee≥98%的α-羟基酮(R)-5),并具有良好的总体收率(51-70%)。该过程的关键步骤是将(S)-2的相应甲硅烷基烯醇醚进行硅定向非对映选择性氧化,其中m-氯过苯甲酸或3-苯基-2-(苯磺酰基)恶唑烷,然后进行快速色谱法和甲硅烷基化反应。